html,
body {
  width: 100%;
  height: 100%;
  padding: 0;
  margin: 0;
}
.content-box {
  display: flex;
  width: 100%;
  height: 100%;
  min-width: 220px;
}
.l-box {
  flex: 0 0 200px;
  /* flex-grow: 0; 不放大
  flex-shrink: 0; 不缩小
  flex-basis: 200px; 固定200px*/
  background: #f57777;
}
.r-box {
  flex-grow: 1;
  background: #bababa;
}
